He is thinking about the lower verse of the Tanka.

I'm sleepy, so I'll go to bed early.

This silkworm has entered the rest period before moulting.

I am very sleepy.

He continued working, fighting off his sleepiness.

I'm feeling sleepy, so I'm going to bed now.

There is a beautiful silk tree planted in the park.

This pipe is for carrying water.

He broke the glass.

He played a broken character in his heart.